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Effect of Metal Cocatalysts and Operating Conditions on the Product Distribution and the Productivity of the CO2 Photoreduction. Ind Eng Chem Res 2022; 61:2963-2972. [PMID: 35264822 PMCID: PMC8895397 DOI: 10.1021/acs.iecr.1c02514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 01/15/2022] [Accepted: 01/21/2022] [Indexed: 12/02/2022]
Abstract
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The CO2 photoreduction is a promising way to convert
one of the most abundant greenhouse gases to valuable chemicals. The
photoreduction in the liquid phase is limited by the low solubility
of CO2 in water, but this point is overcome here by using
an innovative photoreactor, which allows one to work up to pressures
of 20 bar, improving the overall productivity. The photoreduction
was performed in the presence of Na2SO3 and
using in primis commercial titanium dioxide (P25) and a set of titania
catalysts functionalized by surface deposition of either monometallic
or bimetallic cocatalysts. The gaseous products were hydrogen and
traces of CO, while, in the liquid phase, formic acid/formate, formaldehyde
and methanol were quantitatively detected. The pH was observed to
shift the products distribution. A neutral environment led mainly
to hydrogen and methanol, while, at pH 14, formate was the most abundant
compound. The trend for monometallic cocatalysts showed enhanced productivity
when using noble metals (i.e., gold and platinum). In order to limit
the cost of the catalytic material, bimetallic cocatalysts were explored,
adding titania with Au+Ag or Au+Pt. This may open to the possibility
of performing the reaction with a smaller amount of the most expensive
metals. In the end, we have expressed some conclusions on the cost
of the photocatalysts here employed, to support the overall feasibility
assessment of the process.
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Sonophotocatalytic degradation of sodium diclofenac using low power ultrasound and micro sized TiO 2. ULTRASONICS SONOCHEMISTRY 2020; 67:105123. [PMID: 32283492 DOI: 10.1016/j.ultsonch.2020.105123] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 05/24/2023]
Abstract
The nonsteroidal anti-inflammatory drug sodium diclofenac (DC) is an emerging water pollutant which resists conventional wastewater treatments. Here the sonophotocatalytic degradation of DC was carried out using micrometric TiO2 (both pristine and Ag-decorated), UV-A irradiation and 20 kHz pulsed ultrasound. Sonophotocatalytic tests were compared with photolysis, sonolysis, sonophotolysis, sonocatalysis and photocatalysis data performed in the same conditions. A synergy index of over 2 was determined for tests with pristine TiO2, while values close to 1.3 were observed for Ag-TiO2. Reaction intermediates were studied by HPLC-MS, showing degradation mechanisms activated by hydroxyl radicals. Similar pathways were identified for photocatalytic and sonophotocatalytic tests, although the latter led to more oxidized compounds. Different reactor configurations (static and dynamic set ups) were studied. Sequential and simultaneous application of UV light and ultrasound led to similar performance. The role of water matrix was investigated using ultrapure and drinking water, showing marked detrimental effects of electrolytes on the DC degradation. Overall, the combined treatment proved more efficient than photocatalysis alone especially in demanding working conditions, like in drinking water matrices.
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Nonlinear desorption activation energy from TPD curves: Analysis of the influence of initial values for the regression procedure. CAN J CHEM ENG 2020. [DOI: 10.1002/cjce.23700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Effect of Carbon Support, Capping Agent Amount, and Pd NPs Size for Bio-Adipic Acid Production from Muconic Acid and Sodium Muconate. NANOMATERIALS 2020; 10:nano10030505. [PMID: 32168904 PMCID: PMC7153248 DOI: 10.3390/nano10030505] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/02/2020] [Accepted: 03/06/2020] [Indexed: 11/21/2022]
Abstract
The effect of support, stabilizing agent, and Pd nanoparticles (NPs) size was studied for sodium muconate and t,t-muconic acid hydrogenation to bio-adipic acid. Three different activated carbons (AC) were used (Norit, KB, and G60) and carbon morphology did not affect the substrate conversion, but it greatly influenced the adipic acid yield. 1% Pd/KB Darco catalyst, which has the highest surface area and Pd surface exposure, and the smallest NPs size displayed the highest activity. Furthermore, the effect of the amount of the protective agent was studied varying metal/protective agent weight ratios in the range of 1/0.00–1/1.20, using KB as the chosen support. For sodium muconate reduction 1% Pd/KB_1.2 catalyst gave the best results in terms of activity (0.73 s−1), conversion, and adipic acid yield (94.8%), while for t,t-muconic acid hydrogenation the best activity result (0.85 s−1) was obtained with 1% Pd/KB_0.0 catalyst. Correlating the results obtained from XPS and TEM analyses with catalytic results, we found that the amount of PVA (polyvinyl alcohol) influences mean Pd NPs size, Pd(0)/Pd(II) ratio, and Pd surface exposure. Pd(0)/Pd(II) ratio and Pd NPs size affected adipic acid yield and activity during sodium muconate hydrogenation, respectively, while adipic acid yield was related by exposed Pd amount during t,t-muconic acid hydrogenation. The synthesized catalysts showed higher activity than commercial 5% Pd/AC.
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Photocatalytic porcelain grés large slabs digitally coated with AgNPs-TiO 2. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:36117-36123. [PMID: 31020536 DOI: 10.1007/s11356-019-05218-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 04/16/2019] [Indexed: 06/09/2023]
Abstract
TiO2 is employed as both photocatalytic and structural materials, leading to its applications in external coatings or in interior furnishing devices, including cement mortar, tiles, floorings, and glass supports. The authors have already demonstrated the efficiency of photoactive micro-sized TiO2 and here its industrial use is reported using the digital printing to coat porcelain grés slabs. Many advantages are immediately evident, namely rapid and precise deposition, no waste of raw materials, thus positively affecting the economy of the process. Data for the thin films deposited by digital printing were compared with those obtained for the conventional spray method. The use of metal-doped TiO2 is also reported so that the photoactivity of these materials can be exploited even under LED light. The digital inkjet printed coatings exhibited superior photocatalytic performance owing to both higher exposed surface area and greater volume of deposited anatase, as well as the greater areal distribution density of thinly and thickly coated regions. Moreover, the presence of TiO2 doped silver increased the efficiency of the materials in NOx degradation both under UVA and LED lights.
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Experimental Characterization of Polymer Surfaces Subject to Corona Discharges in Controlled Atmospheres. Polymers (Basel) 2019; 11:polym11101646. [PMID: 31658775 PMCID: PMC6836313 DOI: 10.3390/polym11101646] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/24/2019] [Accepted: 10/08/2019] [Indexed: 12/05/2022] Open
Abstract
Polymeric dielectrics are employed extensively in the power transmission industry, thanks to their excellent properties; however, under normal operating conditions these materials tend to degrade and fail. In this study, samples of low-density polyethylene, polypropylene, polymethyl methacrylate, and polytetrafluorethylene were subjected to corona discharges under nitrogen and air atmospheres. The discharges introduced structural modifications over the polymer surface. From a chemical perspective, the alterations are analogous among the non-fluorinated polymers (i.e., polyethylene (PE), polypropylene (PP), and polymethyl methacrylate (PMMA)). A simulation of the corona discharge allowed the identification of highly reactive species in the proximity of the surface. The results are consistent with the degradation of insulating polymers in high-voltage applications due to internal partial discharges that ultimately lead to the breakdown of the material.
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Bio Adipic Acid Production from Sodium Muconate and Muconic Acid: A Comparison of two Systems. ChemCatChem 2019. [DOI: 10.1002/cctc.201900343] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Micro-TiO 2 coated glass surfaces safely abate drugs in surface water. JOURNAL OF HAZARDOUS MATERIALS 2019; 363:328-334. [PMID: 30321837 DOI: 10.1016/j.jhazmat.2018.09.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 06/08/2023]
Abstract
The ingredients of Pharmaceuticals and Personal Care Products (PPCPs) persist in water and conventional treatment plants are not able to remove them efficiently. Sonochemical treatment is insufficient to mineralize organics such as ibuprofen into CO2 and H2O. TiO2 degrades ibuprofen (IBP) under UV light; however, it does not reach a high grade of conversion. Here, we investigated the mineralization of ibuprofen to CO2 by TiO2 UV-C photocatalysis. We replaced nano-sized P25 (the standard catalyst) with a micro-sized commercial sample of TiO2 to preclude the use of nanoparticles which are dangerous for human health and because typical filtration systems are expensive and inefficient. We deposited micro-TiO2 on glass Raschig rings to ensure an easy recovery and reuse of the photocatalyst and we studied its performance both with a batch and a continuous reactor. Micro-TiO2 mineralized 100% of IBP in 24 h. TiO2-coated glass Raschig rings degraded 87% of IBP in 6 h of UV-C irradiation in a continuous reactor, with a mineralization of 25%. Electronspray ionization mass spectrometer (ESI-MS, positive mode) analyses identified 13 different byproducts and we hypothised a degradration pathway for IBP degradation.
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High pressure CO2 photoreduction using Au/TiO2: unravelling the effect of co-catalysts and of titania polymorphs. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00286c] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A series of Au/TiO2 based catalysts with low gold loading (0.1–0.5 wt%) were prepared by a modified deposition–precipitation method and their activity was tested for CO2 photoreduction in the liquid phase at high pressure (7 bar).
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Ultrasound-assisted impregnation for high temperature Fischer-Tropsch catalysts. ULTRASONICS SONOCHEMISTRY 2018; 48:523-531. [PMID: 30080581 DOI: 10.1016/j.ultsonch.2018.06.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 06/20/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
A fraction of the petroleum extracted from oil reservoirs contains associated natural gas. Rather than building infrastructure to recover low volumes of this natural gas, the industry flares or vents it to the atmosphere, which contributes to atmospheric greenhouse gas emissions but also reduces the air quality locally because it contains gaseous sulphur and nitrogen compounds. Converting the natural gas (NG) to hydrocarbons with a small-scale two-step gas-to-liquids process, is an alternative to flaring and venting. In the first step, NG reacts with oxygen to form syngas (Catalytic Partial Oxidation) and in the second step the syngas reacts over metallic catalysts to form higher paraffins at 210 °C to 300 °C-Fischer Tropsch synthesis (FT). For the first time, we synthesize bimetallic FeCo FT catalysts with ultrasound. An ultrasonic horn agitates the solution during the entire impregnation process. The active phase dispersion of the sonicated catalysts was superior to the catalyst synthesized without ultrasound, while reducing the impregnation time by a factor of three. We tested our catalysts in a lab-scale, fixed-bed reactor at 270 °C and 300 °C, and achieved 80% conversion over 3-days on stream and a 40% yield of C2+.
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Experimental methods in chemical engineering: Temperature programmed reduction-TPR. CAN J CHEM ENG 2018. [DOI: 10.1002/cjce.23317] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Micro-sized TiO 2 as photoactive catalyst coated on industrial porcelain grès tiles to photodegrade drugs in water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:20348-20353. [PMID: 28452026 DOI: 10.1007/s11356-017-9066-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
Pharmaceutical compounds and their metabolites raise worrying questions because of their continuous release and lack of efficient removal by conventional wastewater treatments; therefore, they are being detected in groundwater, surface water and drinking water in increasing concentrations. Paracetamol and aspirin are two of the most commonly used drugs employed as fever reducer, analgesic and anti-inflammatory. They and their metabolites are very often found in river water, so their degradation is necessary in order to render water suitable for human consumption. The present work is focused on the comparison of the photocatalytic performance of industrial active grés porcelain tiles covered with a commercial micro-sized TiO2 by industrial process using either conventional spray deposition or innovative digital printing methods. The photodegradation of two commonly used drugs, namely aspirin and paracetamol, was investigated both individually and as a mixture, in both deionized and tap water. The results reveal the full conversion of the drugs and the significant role of the photocatalytic tiles in the mineralization processes leading to harmless inorganic species. In particular, the digitally printed tiles exhibited better photodegradation performance for both drugs compared to the spray deposited tiles. No deactivation was observed on both photocatalytic tiles.
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Production and application of O 2 enriched air produced by fresh and salt water desorption in chemical plants. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 217:621-628. [PMID: 29649734 DOI: 10.1016/j.jenvman.2018.03.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/23/2018] [Accepted: 03/31/2018] [Indexed: 06/08/2023]
Abstract
Oxygen enriched air intensifies oxidation processes since smaller reactors reach the same conversion of typical unit operations that employ simple air as reactant. However, the cost to produce pure oxygen or oxygen enriched air with traditional methods, i.e. cryogenic separation or membrane technologies, may be unaffordable. Here, we propose a new continuous technology for gas mixture separation, focusing on the production of oxygen enriched air as a case study. This operation is an absorption-desorption process that takes advantage of the higher oxygen solubility in water compared to nitrogen. In a pressurized solubilisation tank, water absorbs air. Subsequently, reducing pressure desorbs oxygen enriched air. PRO/II 9.3 (Simsci-Scheider Electrics) simulated, optimized, and calculated the capital and operative expenses of this technology. Moreover, we tested for the first time salt water instead of distilled water as appealing possibility for chemical plant near sea and ocean. We varied the inlet water flowrate between 5 and 15 m3/h. The optimum operative absortion unit pressure is 15-35 barg. After degassing, water may be recycled. With salt water, the extracted quantity of enriched air decreases compared with the desorption from fresh water (20% less), while the concentration of oxygen is independent from the salt concentration. The cost of enriched air at the optimum condition is 2-3.35 EUR/Nm3.
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Comparison of Branched and Linear Perfluoropolyether Chains Functionalization on Hydrophobic, Morphological and Conductive Properties of Multi-Walled Carbon Nanotubes. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E176. [PMID: 29562718 PMCID: PMC5869667 DOI: 10.3390/nano8030176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 12/03/2022]
Abstract
The functionalization of multi-walled carbon nanotubes (MW-CNTs) was obtained by generating reactive perfluoropolyether (PFPE) radicals that can covalently bond to MW-CNTs' surface. Branched and linear PFPE peroxides with equivalent molecular weights of 1275 and 1200 amu, respectively, have been thermally decomposed for the production of PFPE radicals. The functionalization with PFPE chains has changed the wettability of MW-CNTs, which switched their behavior from hydrophilic to super-hydrophobic. The low surface energy properties of PFPEs have been transferred to MW-CNTs surface and branched units with trifluoromethyl groups, CF₃, have conferred higher hydrophobicity than linear units. Porosimetry discriminated the effects of PFPE functionalization on meso-porosity and macro-porosity. It has been observed that reactive sites located in MW-CNTs mesopores have been intensively functionalized by branched PFPE peroxide due to its low average molecular weight. Conductivity measurements at different applied pressures have showed that the covalent linkage of PFPE chains, branched as well as linear, weakly modified the electrical conductivity of MW-CNTs. The decomposed portions of PFPE residues, the PFPE chains bonded on carbon nanotubes, and the PFPE fluids obtained by homo-coupling side-reactions were evaluated by mass balances. PFPE-modified MW-CNTs have been characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), static contact angle (SCA), surface area, and porosity measurements.
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Simultaneous photodegradation of VOC mixture by TiO 2 powders. CHEMOSPHERE 2018; 193:198-206. [PMID: 29131978 DOI: 10.1016/j.chemosphere.2017.11.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 06/07/2023]
Abstract
Volatile and semi volatile organic compounds' concentration have dramatically increased in indoor environments in recent years. UV light promotes titanium dioxide, which oxidises various molecules; however, most of the studies report the degradation of a single VOC. Here, we investigate the photo-oxidation of 17 molecules in mixture to have a realistic test of TiO2 efficacy. We compare P25, a nanometric catalyst, and 1077, a micrometric sample, that poses less health concerns. A proton-transfer-reaction mass spectrometer measured online the concentration of all the pollutants simultaneously. Aldehydes compete for the adsorption on both the catalyst's active sites and thus they degrade 70% and 55% with P25 and 1077 respectively. Considering the single pollutant oxidation, instead, aldehydes fully oxidize. Even though benzene is recalcitrant to degradation, P25 and 1077 reduced toluene's concentration to 97% and 96% in 55 min, respectively. Acetonitrile is refractory to photocatalysis.
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Production of oxygen-enriched air via desorption from water: Experimental data, simulations and economic assessment. Comput Chem Eng 2017. [DOI: 10.1016/j.compchemeng.2016.07.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Aspirin and paracetamol removal using a commercial micro-sized TiO 2 catalyst in deionized and tap water. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:12646-12654. [PMID: 27770326 DOI: 10.1007/s11356-016-7781-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Abstract
Micro-sized TiO2 catalyst was employed to degrade pharmaceutical compounds, i.e. aspirin and paracetamol, two of the most widely used drugs, purchasable without prescription. Their active agents, acetylsalicylic acid and acetaminophen, are characterized by different substituent groups, linked to the aromatic ring, which affect both the photodegradation and mineralization processes. The experimental conditions highlight the relationship between the nature of the pristine molecules, their degradation mechanisms, their mutual interference and the water's role. The research started from model systems with a single pollutant to the mixture of them and finally by moving from deionized water to tap water.
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Fe-based heterogeneous catalysts for the Fischer-Tropsch reaction: Sonochemical synthesis and bench-scale experimental tests. ULTRASONICS SONOCHEMISTRY 2017; 34:774-780. [PMID: 27773304 DOI: 10.1016/j.ultsonch.2016.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 07/12/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
The sonochemical synthesis of nanostructured materials owes its origins to the extreme conditions created during acoustic cavitation, i.e., the formation of localized hot spots in the core of collapsing bubbles in a liquid irradiated with high intensity ultrasound (US). In particular, in the present work a sonochemical synthesis has been investigated for the production of three different iron-based samples supported on SiO2 and loaded with different metals and promoters (10 %wt of Fe; 30 %wt of Fe; 30 %wt of Fe, 2 %wt of K and 3.75 %wt of Cu) active in the Fischer-Tropsch (FT) process. Sonochemically synthesized heterogeneous catalysts were characterized by BET, XRPD, TPR, ICP, CHN, TEM, SEM and then tested in a fixed bed FT-bench-scale rig fed with a mixture of H2 and CO at a H2/CO molar ratio equal to 2, at activation temperatures of 350-400°C and reaction temperatures of 250-260°C. The experimental results showed that the ultrasonic samples are effective catalysts for the FT process. Notably, increasing the activation temperature increased CO conversion, while product selectivity did not diminish. All the sonochemically prepared samples presented in this work provided better catalytic results compared to the corresponding traditional FT impregnated catalysts.
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Biogas: a Possible New Pathway to Methanol? ACTA ACUST UNITED AC 2017. [DOI: 10.1016/b978-0-444-63965-3.50089-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Robust optimization of the heteroextractive distillation column for the purification of water/acetic acid mixtures using p -xylene as entrainer. Comput Chem Eng 2016. [DOI: 10.1016/j.compchemeng.2016.09.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Sol-gel hybrid coatings containing silica and a perfluoropolyether derivative with high resistance and anti-fouling properties in liquid media. J Fluor Chem 2016. [DOI: 10.1016/j.jfluchem.2016.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Copper NPs decorated titania: A novel synthesis by high energy US with a study of the photocatalytic activity under visible light. ULTRASONICS SONOCHEMISTRY 2016; 31:295-301. [PMID: 26964952 DOI: 10.1016/j.ultsonch.2016.01.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/24/2015] [Accepted: 01/14/2016] [Indexed: 05/12/2023]
Abstract
The most important drawback of the use of TiO2 as photocatalyst is its lack of activity under visible light. To overcome this problem, the surface modification of commercial micro-sized TiO2 by means of high-energy ultrasound (US), employing CuCl2 as precursor molecule to obtain both metallic copper as well as copper oxides species at the TiO2 surface, is here. We have prepared samples with different copper content, in order to evaluate its impact on the photocatalytic performances of the semiconductor, and studied in particular the photodegradation in the gas phase of some volatile organic molecules (VOCs), namely acetone and acetaldehyde. We used a LED lamp in order to have only the contribution of the visible wavelengths to the TiO2 activation (typical LED lights have no emission in the UV region). We employed several techniques (i.e., HR-TEM, XRD, FT-IR and UV-Vis) in order to characterize the prepared samples, thus evidencing different sample morphologies as a function of the various copper content, with a coherent correlation between them and the photocatalytic results. Firstly, we demonstrated the possibility to use US to modify the TiO2, even when it is commercial and micro-sized as well; secondly, by avoiding completely the UV irradiation, we confirmed that pure TiO2 is not activated by visible light. On the other hand, we showed that copper metal and metal oxides nanoparticles strongly and positively affect its photocatalytic activity.
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First-principles models and sensitivity analysis for the lignocellulosic biomass-to-methanol conversion process. Comput Chem Eng 2016. [DOI: 10.1016/j.compchemeng.2015.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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NOxdegradation in a continuous large-scale reactor using full-size industrial photocatalytic tiles. Catal Sci Technol 2016. [DOI: 10.1039/c5cy01627d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A gas-flow photoreactor working with a UV-A lamp or under direct sunshine to test materials of large size.
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Surface properties and anti-fouling assessment of coatings obtained from perfluoropolyethers and ceramic oxides nanopowders deposited on stainless steel. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2015.08.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Online model-based optimization and control for the combined optimal operation and runaway prediction and prevention in (fed-)batch systems. Chem Eng Sci 2015. [DOI: 10.1016/j.ces.2015.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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High-loaded Fe-supported catalyst for the thermochemical BtL-FT process: Experimental results and modelling. CAN J CHEM ENG 2015. [DOI: 10.1002/cjce.22357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nano and micro-TiO2 for the photodegradation of ethanol: experimental data and kinetic modelling. RSC Adv 2015. [DOI: 10.1039/c5ra05385d] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In this work we show the possibility of using pigmentary TiO2-powders as photocatalysts and we develop a kinetic model which is able to follow the behavior of nano-TiO2versus micro-TiO2 in ethanol degradation.
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CO2 photoconversion to fuels under high pressure: effect of TiO2 phase and of unconventional reaction conditions. Catal Sci Technol 2015. [DOI: 10.1039/c5cy00756a] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Effect of CO2 saturation and reactor pressure on H2 (full triangles) and CH4 (circles) productivity at pH = 11.4, T = 65 °C. H2 productivity (empty triangles) at pH 5.5, T = 65 °C. Sample 0.1 wt% Au/P25.
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38
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Aromatization of propane: Techno-economic analysis by multiscale “kinetics-to-process” simulation. Comput Chem Eng 2014. [DOI: 10.1016/j.compchemeng.2014.10.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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39
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Simulation and Related Experimental Validation of Acetic Acid/Water Distillation Using p-Xylene as Entrainer. Ind Eng Chem Res 2014. [DOI: 10.1021/ie502758v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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Ultrasonic free fatty acids esterification in tobacco and canola oil. ULTRASONICS SONOCHEMISTRY 2014; 21:1969-75. [PMID: 24534067 DOI: 10.1016/j.ultsonch.2014.01.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 01/16/2014] [Accepted: 01/26/2014] [Indexed: 05/08/2023]
Abstract
Ultrasound accelerates the free fatty acids esterification rate by reducing the mass transfer resistance between methanol in the liquid phase and absorbed organic species on Amberlyst®46 catalyst. The reaction rates of canola oil is three times greater than for tobacco seed oil but half the reaction rate of pure oleic acid as measured in a batch reactor. The beneficial effects of ultrasound vs. the conventional approach are more pronounced at lower temperatures (20°C and 40°C vs. 63°C): at 20°C, the free fatty acids conversion reaches 68% vs. 23% with conventional mechanical stirring. The increased conversion is attributed to acoustic cavitation that increases mass transfer in the vicinity of the active sites. The Eley-Rideal kinetic model in which the concentration of the reacting species is expressed taking into account the mass transfer between the phases is in excellent agreement with the experimental data. Ultrasound increases the mass transfer coefficient in the tobacco oil 6 and 4.1 fold at 20°C and 40°C, respectively.
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41
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Abstract
Carotenoids in CPO can be preserved during the deacidification processes performed under mild conditions.
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43
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Porous TiO2 microspheres with tunable properties for photocatalytic air purification. ULTRASONICS SONOCHEMISTRY 2013; 20:445-451. [PMID: 22892199 DOI: 10.1016/j.ultsonch.2012.07.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/09/2012] [Accepted: 07/09/2012] [Indexed: 06/01/2023]
Abstract
The synthesis of highly-crystalline porous TiO(2) microspheres is reported using ultrasonic spray pyrolysis (USP) in the presence of colloidal silica as a template. We have exploited the interactions between hot SiO(2) template particles surface and TiO(2) precursor that occur during reaction inside the droplets, to control the physical and chemical properties of the resulting particles. Varying the SiO(2) to titanium precursor molar ratio and the colloidal silica dimension, we obtained porous titania microspheres with tunable morphology, porosity, BET surface area, crystallite size, band-gap, and phase composition. In this regard, we have also observed the preferential formation of anatase vs. rutile with increasing initial surface area of the silica template. The porous TiO(2) microspheres were tested in the photocatalytic degradation of nitrogen oxides (NO(x)) in the gas phase. USP prepared nanostructured titania samples were found to have significantly superior specific activity per surface area compared to a commercial reference sample (P25 by Evonik-Degussa).
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44
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Microwave-assisted digestion of organic samples: how simple can it become? Talanta 2012; 98:272-6. [PMID: 22939159 DOI: 10.1016/j.talanta.2012.06.079] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/24/2012] [Accepted: 06/30/2012] [Indexed: 10/28/2022]
Abstract
Advancements in sample preparation for performing trace analysis of inorganic analytes are coming from the dissemination of microwave-assisted procedures, but there is still room for improvements by looking for simple and easily applied procedures. Recently it was proposed a new approach called single reaction chamber with capability for digestions at high pressures and temperatures using simple vials and racks. This was a limitation of former cavity microwave ovens with closed vessels. It was demonstrated here that the use of single reaction chamber approach allows the implementation of efficient digestions using diluted solutions of nitric acid and also allows addressing a critical need of sample preparation for inorganic analysis by running mixed batches of samples. The feasibility of this procedure was demonstrated for organic samples and accuracy was proved by using certified reference materials of apple leaves, bovine liver and whole milk powder. Digestions performed of whole milk powder and bovine liver using 2.0 mol L(-1) nitric acid solution plus concentrated hydrogen peroxide at 240 °C led to residual carbon contents of 0.825 and 1.50% and residual acidities of 1.04 and 0.618 mol L(-1), respectively. These parameters are fully compatible with further measurements using ICP OES or ICP-MS. Al, Cu, Fe, Mn, Mo, Rb, Se, Sr, and Zn were accurately determined by ICP OES or ICP-MS depending on their concentrations in digests.
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45
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Simultaneous ultrasound and microwave new reactor: detailed description and energetic considerations. ULTRASONICS SONOCHEMISTRY 2012; 19:872-876. [PMID: 22227552 DOI: 10.1016/j.ultsonch.2011.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 12/06/2011] [Accepted: 12/10/2011] [Indexed: 05/31/2023]
Abstract
A new reactor in which microwaves (MW), delivered by a coaxial dipole antenna, and ultrasound (US), delivered by a metallic horn, can be simultaneously used in a liquid to perform different types of processes, widely referenced in literature, is presented in detail. Calibrations of thermal energy delivered to two liquids having very different dipolar moments (i.e. water and cyclohexane) using MW and US, both separately and simultaneously, are performed by employing the traditional calorimetric method. The main results are: (i) MW and US used simultaneously increase the thermal energy delivered to the two liquids with respect to their separate use, but differently using water or cyclohexane, and (ii) the total power absorbed by polar or non polar liquids is very different, both using MW and US.
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46
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Photocatalytic NOx abatement: the role of the material supporting the TiO2 active layer. JOURNAL OF HAZARDOUS MATERIALS 2012; 211-212:203-207. [PMID: 22119301 DOI: 10.1016/j.jhazmat.2011.10.095] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 10/21/2011] [Accepted: 10/30/2011] [Indexed: 05/31/2023]
Abstract
The importance of the choice of a suitable substrate as supporting material for photoactive TiO(2), either in the form of powders or thin films or in photoactive paints, is frequently disregarded. In this paper four different supports (stainless steel, sand-blasted stainless steel, Teflon and glass) are object of investigation. The final aim is to verify the presence of interactions between the photocatalyst (AEROXIDE(®) TiO(2) P25 by Evonik Degussa Corporation) and the support, directly involved in the photocatalytic activity in the NO(x) abatement. The characterization results have been correlated with the photoactivity of the different samples. In particular, a coating of about 6-9 μm seems to allow a photocatalytic result free from any positive or negative interference with the supporting material, therefore giving reliable results about the photoactivity of the TiO(2) under investigation.
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Feasibility study for the production of biofuels from Brassicaceae spp. and Nicotiana tabacum oilseeds and from by-products or waste materials. J Biotechnol 2010. [DOI: 10.1016/j.jbiotec.2010.08.450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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48
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Vegetable Oil Deacidification by Amberlyst: Study of the Catalyst Lifetime and a Suitable Reactor Configuration. Ind Eng Chem Res 2010. [DOI: 10.1021/ie901980c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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49
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Ultrasound and microwave assisted synthesis of high loading Fe-supported Fischer-Tropsch catalysts. ULTRASONICS SONOCHEMISTRY 2010; 17:610-616. [PMID: 20005145 DOI: 10.1016/j.ultsonch.2009.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 11/05/2009] [Accepted: 11/08/2009] [Indexed: 05/28/2023]
Abstract
Supported iron-based Fischer-Tropsch (FT) catalysts with high loading of active metal have been prepared using both traditional and innovative methods. In these latter the impregnation of silica support has been performed by adding a step involving an ultrasound (US) or a microwave (MW) treatment to improve the metal deposition and to increase the catalyst activity. FT results have indicated the catalysts prepared by US as the most efficient, particularly when sonication is performed in argon atmosphere. MW prepared samples have given results very similar to those obtained with the traditional method. In order to explain the different catalytic activity, all the samples have been characterized by BET, TPR, SEM, TEM, XRD and micro-Raman analyses.
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50
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Low Temperature De-acidification Process of Animal Fat as a Pre-Step to Biodiesel Production. Catal Letters 2009. [DOI: 10.1007/s10562-009-0228-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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